Grate clip for traveling grate stokers



F. B. HALL v GRAT E CLIP FOR TRAVELING GRATE STOKERS Oct. 18, 1949.

2 Sheets$heet 1 Filed Jan. 30, 1948 A 6 in? VIII/l2 w\\\\\\\\\ w A w IQTTORNEY Oct. 18, 1949; HALL I 2,485,379

GRATE CLIP FOR TRAVELING GRATE STOKERS Filed Jan, so, 1948 I 2 Sheets-Sheet 2 IN VEN TOR F1750 B. HALL Arron/V5) Patented Oct. 18, 1949 GRATE CLIP FOR TRAVELING GRATE STOKERS Fred B. Hall, Worcester, Mass, asslgnor to Riley Stoker Corporation, Worcester, Mass, a. corporation of Massachusetts Application January 30, 1948, Serial No. 5,424

4 Claims.

'1 This invention relates to grate clips for traveling grate stokers, and more particularly to grate clips of the general type shown in the patent to Krieger No. 1,917,652, granted July 11, 1933, such clips having depressed portions at their trailing ends and elevated fuel supporting portions at their leading ends which overlie the depressed portions of the adjacent clips.

It is one object of the invention to provide a grate clip which will ensure a more efficient distribution of the air for combustion.

It is a further object of the invention to provide a grate clip which will to a considerable extent avoid the sifting of fine particles of fuel or ash into the air compartments of the stoker.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto. I

Referring to the drawings illustrating one embodiment of the invention, and in which like reference numerals indicate like parts,

Fig. 1 is a perspective view of a grate clip; 1

Fig. 2 is a longitudinal section through a portion of a traveling grate, showing the grate clips in side elevation;

Fig. 3 is a view similar to Fig. 2 but on a smaller scale, and further showing the general arrangement of the rear portion of the stoker; and

Fig. 4 is an enlarged section taken on the line 44 of Fig. 2.

Referring first to Figs. 2 and 3, there is shown a transverse horizontal rear girder l supported at each end on a vertical pedestal II. Two or more members l2 (one only being shown) are mounted on the rear face of the girder to provide curved tracks for endless parallel grate chains which pass around the girder. These chains are formed of links [4 pivotally connected to each other by means of pins ii. The pins carry rollers l6 which roll upon the track I2 as the chain moves thereover, and a shoe I8 is provided to guide the chain onto the lower track (not shown), all of which is well known in this art. The space H) in front of the girder is enclosed by a compartment bottom plate 20 and an air seal 2|, and air is supplied to this space under pressure from any suitable source.

A series of spaced parallel grate supporting bars As best shown in Figs. 1 and 4, each grate clip 21 is in the form of an elongated narrow metal body comprising a vertical web 28 and a flange 29 extending horizontally from one side of the web at the upper edge thereof. The leading portion 3| of the clip is elevated to provide the fuel support proper, whereas the trailing portion 32 is depressed and at assembly extends beneath the portion 3| of the corresponding clip in the next row. The fuel supporting portion of the flange 29 is preferably somewhat thicker than the remainder of the flange, and on its edge there are provided a series of spaced Z-shaped ribs 33 forming tortuous channels 34 therebetween for the flow of air upwardly to the fuel bed. Spaced transverse grooves 36 are provided in the top of the fuel supporting portion 3| to aid in distributing the air laterally. A boss or enlargement 31 is provided on the web 28, intermediate the ends of the clip, and this boss is formed with a T- shaped slot or opening 38 therethrough which fits the adjacent member 25 somewhat loosely. This boss 31 is offset from the center of gravity of the clip in a direction toward the trailing portion 32, so that the leading end of the clip will rest by gravity on the trailing portion of the adjacent clip.

Each grate clip 21 is provided with means for ensuring a substantially uniform distribution 'of air among the channels 34 and for avoiding the deposit of fuel or ash particles in the air chamber l9. For this purpose a flange 40 extends horizontally from the web 28 beneath and spaced downwardly from the fuel supporting portion of the flange 29 and forwardly to the leading end of the clip. A portion of this flange 40 forms the upper wall of the slot 38. Three small shallow notches 42, 43 and 44 are provided in the edge of the flange 40 in order that air may flow upwardly therethrough from the chamber I9. In addition a large deep notch 46 is provided in this flange near the leading end of the clip in order that fine particles of fuel or ash which have been deposited on the flange may be discharged therethrough as the clip tips downwardly at the rear of the stoker. Preferably the notch 46 extends all the way to the web 28. A small shallow notch 48 is provided in the edge of the flange 29 on the trailing portion of the clip in position to register with the large notch 46 of the adjacent clip. Thus the flange 29 on the trailing portion of one clip will substantially close the notch 46 thereabove, permitting only such air flow as may take place through the notch 48.

It will now be apparent that in the operation of the invention, the air flowing upwardly from the chamber l9 must pass through the small notches or openings 42, 43, 44 and 48 in order to reach the air channels 34 which direct it into the fuel bed carried by the clips. Consequently these notches provide metering restrictions which will prevent excessive flow even though portions of the fuel bed may be relatiyely-th'in. 'In this way, the air distribution among the various grate clips is made more uniform. Furthermore the air distribution among the various air channels 34 a given clip is rendered more unifiorm by -the elimr ination of the blasting effect encountered certain prior clips. Fine particles of ash and fuel which may sift thronglithe air channelsftfi will for the most part collect on thelower-flange 40 rather than fall into the air chamber [9. As the clips tip downwardly at theend ofgthestoher (see Fig. 3), adjacent rows of clips will separate, and these particles of siftings will be discharged by gravity through the large openings 46. The improved clip thus provides for more efiicient combustion, and eliminates the necessity for cleaning out the stoker airtchambers at frequent intervals.

.'.H aving-thus described my invention, what I claim. as newrand desire tosecureby Letters Patent; is:

1. -A grate clip for traveling grate stokers in the form of an elongated narrow metal body comprising a vertical web, a flange at the upper edge of the -web providingan elevated fuel supporting surfaceatthe lea ding end ofthe clip and adepressed surface at the trailing end of the clip in position to un derlie the leading end of-an adjacent clip at assembly, the fuel sup portingportion of the flange having channels therein for the flow of air to the fuel, and a lower fla lo a ed e t th f l ub rt n P iQ the rs m t gdfiang 32d d w watdl li fe r m th S id Q r.--f e e en ne near h ad n ndq .ihecl p, nd. 1 Qp ll g tne i hrqu Q T- e W 3. up a id o h sa e han el A rat cl a s t iqrthm cl im. n w i h th QP- n h'muehth lower flan a e in. h form of small notches in the edge thereof.

3- A. ra l a s i i t a n 1.. ewibi a relatively large opening is provided in the lower flange near the leading end of the clip for the discharge of fine fuel or ash particles from the upper surface of the lower flange as the clip tips downwardly at the end of the stoker, this large opening being adapted to be located directly above thetrailing depressed portion of an adjacent similar clip when the clips are in their normal fuel-burning positions.

4. A grate clip for traveling grate stokers in the, form or elongated narrow metal body comprising a vertical web, a flange at the upper edge of the web providing an elevated fuel supporting surface atthe leading end of the clip andad ep'res sed surface at the trailing end of the"cl-ip in position to underlie the leading end ,oj arnadiaoent -clip at assembly, the fuel supporting portion of the flange having a series of channel's inits edge for the flow of air to the fuel, and a lower flange projecting from the web beheath. the :tueLsupportin portion of the first mentioned fiangeland extending near the leading .endoof-thel'clip,othenlower flange having small notches in. itsedgefor the flow of air upwardly to,thesaidchannelsand. arelatively large notch nealfthe leading end of the clip. for the discharge -'REEEBENGES CITE liheiellew y rsieieaqe e ee r the file 9 meet UN TED SEATES PATENTS 

